ABSTRACT
Aim: To evaluate the effect of intra-canal cryotherapy on interleukin-1β
and interleukin-10 expression in teeth with symptomatic apical periodontitis.
Methodology: Forty-eight single rooted teeth in patients with symptomatic apical periodontitis
were randomly divided into 4 groups according to the irrigation protocol.
Group I (control); 5% sodium hypochlorite at room temperature. Group II; 5% cold
sodium hypochlorite (2-5°C). Group III; final rinse with 20 mL of 5% cold sodium
hypochlorite (2-5°C) for 5 minutes. Group IV; final rinse with 20 mL of cold saline (2-
5°C) for 5 minutes. Paper point passing 2 mm beyond the apex was used to collect periapical
fluid before, immediately after mechanical instrumentation and after one week to
characterize the mRNA expression of IL-1β and Il-10 using real-time polymerase chain
reaction (PCR). Statistical analysis was performed using one-way ANOVA to compare
between all groups. Results: Our results revealed statistically significant (at P≤ 0.05)
down regulation of IL-1β gene expression levels in all groups after one week with no
statistically significant difference between the four groups and statistically significant
(at P≤ 0.05) up regulation of IL-10 gene expression levels in all groups after one week.
Conclusion: All the cryotherapy irrigation protocols showed lower levels of expression
of the pro-inflammatory mediators (interleukin-1β) and higher levels of expression of
the anti-inflammatory mediator (interleukin-10) than the control group after one week.